7 вариант: 1) 5/6 − 1/3; 2) 7 − 3 3/13; 3) 2 7/18 + 5 5/12; 4) 8 5/6 − 2 7/8; 5) 1/6 × 6/7; 6) 3 1/3 × 33/100; 7) 6/5 : 4/3; 8) 13 : 5 4/7

1. \(\frac{5}{6}-\frac{1}{3}=\frac{5}{6}-\frac{2}{6}=\frac{3}{6}=\frac{1}{2}\).
2. \(7-3\frac{3}{13}=7-\frac{42}{13}=\frac{91-42}{13}=\frac{49}{13}=3\frac{10}{13}\).
3. \(2\frac{7}{18}+5\frac{5}{12}=7+\frac{14}{36}+\frac{15}{36}=7\frac{29}{36}\).
4. \(8\frac{5}{6}-2\frac{7}{8}=6+\frac{20}{24}-\frac{21}{24}=5\frac{23}{24}\).
5. \(\frac{1}{6}\times\frac{6}{7}=\frac{1}{7}\).
6. \(3\frac{1}{3}=\frac{10}{3}\), поэтому \(\frac{10}{3}\times\frac{33}{100}=\frac{11}{10}=1\frac{1}{10}\).
7. \(\frac{6}{5}:\frac{4}{3}=\frac{6}{5}\times\frac{3}{4}=\frac{18}{20}=\frac{9}{10}\).
8. \(13:5\frac{4}{7}=13:\frac{39}{7}=13\times\frac{7}{39}=\frac{7}{3}=2\frac{1}{3}\).

Ответ: 1) \(\frac{1}{2}\); 2) \(3\frac{10}{13}\); 3) \(7\frac{29}{36}\); 4) \(5\frac{23}{24}\); 5) \(\frac{1}{7}\); 6) \(1\frac{1}{10}\); 7) \(\frac{9}{10}\); 8) \(2\frac{1}{3}\).